Practical advice (helpful hints & suggestions) requested from those of you
who have successfully checked camber at home (to sufficient accuracy).

If you have never checked your automotive alignment camber at home, you
probably won't be able to add much practical value to this thread; however
if you have actually measured your wheel camber with sufficient accuracy at
home, you almost certainly can add valuable pragmatic hints to this thread
(such that we'll all learn from your experience).

I am researching whether automotive alignment camber quick checks are yet
possible to a reasonable degree of accuracy using a free app on a common
mobile device (either iOS or Android, both of which I own).

A search does find a variety of methods to check camber at home:
https://www.google.com/search?q=check+camber+at+home
where some of those articles used mobile phone apps
(e.g., XXXXXX)

Here I am just asking for advice from those of you who have successfully
checked your camber at home using your smartphone to measure the angles to
sufficient accuracy.

To find apps which measure angles to sufficient accuracy, I have already
run a variety of Google searches of the general form:
1. review best ios free app angle automotive alignment camber accurate
2. review best android free app angle automotive alignment camber accurate

Some hits from the iOS searches are as follows:
A. Wheel Align for ALiSENSOR Wheel By Gloi AB
https://itunes.apple.com/us/app/whee...or/id513879710
B. iHandy Level Free By iHandy Inc.
https://itunes.apple.com/us/app/ihan...ee/id299852753
C. Clinometer + bubble level + slope finder (3 in 1) By Peter Breitling
https://itunes.apple.com/us/app/clin...el/id286215117

Some hits from the Android searches are as follows:
A. Clinometer + bubble level By plaincode
https://play.google.com/store/apps/d...ode.clinometer
B. iHandy Level Free By iHandy Ltd.
https://play.google.com/store/apps/d...arpenter.level
C. Angle Meter PRO By nakhon phagdeechat
https://play.google.com/store/apps/d....anglemeterpro

The amount of useless responses to this thread can be minimized simply by
asking those who don't care to or who haven't ever successfully checked
their camber at home to NOT respond (they're not going to be able to tell
us anything we don't already know - all they're going to do is clutter up
this thread to make it harder to be useful to others).

However, if you have ever attempted to check your camber at home using a
smart phone angle measuring tool, your insight, hints, and advice would be
greatly appreciated (and would be generally useful to many people).